KVM: PPC: Book3S HV: Modify guest entry/exit paths to handle radix guests

This adds code to  branch around the parts that radix guests don't
need - clearing and loading the SLB with the guest SLB contents,
saving the guest SLB contents on exit, and restoring the host SLB
contents.

Since the host is now using radix, we need to save and restore the
host value for the PID register.

On hypervisor data/instruction storage interrupts, we don't do the
guest HPT lookup on radix, but just save the guest physical address
for the fault (from the ASDR register) in the vcpu struct.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index fb73518bd03bd9258c2fb355d92409d7d7615b5c..da1421a4d6f29f070c9a940fcd00acc80926b6f2 100644 (file)
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -606,6 +606,7 @@ struct kvm_vcpu_arch {
        ulong fault_dar;
        u32 fault_dsisr;
        unsigned long intr_msr;
+       ulong fault_gpa;        /* guest real address of page fault (POWER9) */
 #endif
 
 #ifdef CONFIG_BOOKE

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 0601e6a7297c64ea4b2129011d32ae42a662ac07..3afa0ad9837ffb281855db730123e9fb3e35722d 100644 (file)
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -498,6 +498,7 @@ int main(void)
        DEFINE(KVM_NEED_FLUSH, offsetof(struct kvm, arch.need_tlb_flush.bits));
        DEFINE(KVM_ENABLED_HCALLS, offsetof(struct kvm, arch.enabled_hcalls));
        DEFINE(KVM_VRMA_SLB_V, offsetof(struct kvm, arch.vrma_slb_v));
+       DEFINE(KVM_RADIX, offsetof(struct kvm, arch.radix));
        DEFINE(VCPU_DSISR, offsetof(struct kvm_vcpu, arch.shregs.dsisr));
        DEFINE(VCPU_DAR, offsetof(struct kvm_vcpu, arch.shregs.dar));
        DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa.pinned_addr));
@@ -537,6 +538,7 @@ int main(void)
        DEFINE(VCPU_SLB_NR, offsetof(struct kvm_vcpu, arch.slb_nr));
        DEFINE(VCPU_FAULT_DSISR, offsetof(struct kvm_vcpu, arch.fault_dsisr));
        DEFINE(VCPU_FAULT_DAR, offsetof(struct kvm_vcpu, arch.fault_dar));
+       DEFINE(VCPU_FAULT_GPA, offsetof(struct kvm_vcpu, arch.fault_gpa));
        DEFINE(VCPU_INTR_MSR, offsetof(struct kvm_vcpu, arch.intr_msr));
        DEFINE(VCPU_LAST_INST, offsetof(struct kvm_vcpu, arch.last_inst));
        DEFINE(VCPU_TRAP, offsetof(struct kvm_vcpu, arch.trap));

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 01f4392a284d0ca07008d2961e19a75b2b00a64a..7fc7a92215097be31ecf00f48b7343fee859ff70 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -518,6 +518,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 /* Stack frame offsets */
 #define STACK_SLOT_TID         (112-16)
 #define STACK_SLOT_PSSCR       (112-24)
+#define STACK_SLOT_PID         (112-32)
 
 .global kvmppc_hv_entry
 kvmppc_hv_entry:
@@ -530,6 +531,7 @@ kvmppc_hv_entry:
         * R1 = host R1
         * R2 = TOC
         * all other volatile GPRS = free
+        * Does not preserve non-volatile GPRs or CR fields
         */
        mflr    r0
        std     r0, PPC_LR_STKOFF(r1)
@@ -549,32 +551,38 @@ kvmppc_hv_entry:
        bl      kvmhv_start_timing
 1:
 #endif
-       /* Clear out SLB */
+
+       /* Use cr7 as an indication of radix mode */
+       ld      r5, HSTATE_KVM_VCORE(r13)
+       ld      r9, VCORE_KVM(r5)       /* pointer to struct kvm */
+       lbz     r0, KVM_RADIX(r9)
+       cmpwi   cr7, r0, 0
+
+       /* Clear out SLB if hash */
+       bne     cr7, 2f
        li      r6,0
        slbmte  r6,r6
        slbia
        ptesync
-
+2:
        /*
         * POWER7/POWER8 host -> guest partition switch code.
         * We don't have to lock against concurrent tlbies,
         * but we do have to coordinate across hardware threads.
         */
        /* Set bit in entry map iff exit map is zero. */
-       ld      r5, HSTATE_KVM_VCORE(r13)
        li      r7, 1
        lbz     r6, HSTATE_PTID(r13)
        sld     r7, r7, r6
-       addi    r9, r5, VCORE_ENTRY_EXIT
-21:    lwarx   r3, 0, r9
+       addi    r8, r5, VCORE_ENTRY_EXIT
+21:    lwarx   r3, 0, r8
        cmpwi   r3, 0x100               /* any threads starting to exit? */
        bge     secondary_too_late      /* if so we're too late to the party */
        or      r3, r3, r7
-       stwcx.  r3, 0, r9
+       stwcx.  r3, 0, r8
        bne     21b
 
        /* Primary thread switches to guest partition. */
-       ld      r9,VCORE_KVM(r5)        /* pointer to struct kvm */
        cmpwi   r6,0
        bne     10f
        lwz     r7,KVM_LPID(r9)
@@ -658,7 +666,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
        beq     kvmppc_primary_no_guest
 kvmppc_got_guest:
 
-       /* Load up guest SLB entries */
+       /* Load up guest SLB entries (N.B. slb_max will be 0 for radix) */
        lwz     r5,VCPU_SLB_MAX(r4)
        cmpwi   r5,0
        beq     9f
@@ -696,8 +704,10 @@ kvmppc_got_guest:
 BEGIN_FTR_SECTION
        mfspr   r5, SPRN_TIDR
        mfspr   r6, SPRN_PSSCR
+       mfspr   r7, SPRN_PID
        std     r5, STACK_SLOT_TID(r1)
        std     r6, STACK_SLOT_PSSCR(r1)
+       std     r7, STACK_SLOT_PID(r1)
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
 BEGIN_FTR_SECTION
@@ -1293,11 +1303,15 @@ mc_cont:
        mtspr   SPRN_CTRLT,r6
 4:
        /* Read the guest SLB and save it away */
+       ld      r5, VCPU_KVM(r9)
+       lbz     r0, KVM_RADIX(r5)
+       cmpwi   r0, 0
+       li      r5, 0
+       bne     3f                      /* for radix, save 0 entries */
        lwz     r0,VCPU_SLB_NR(r9)      /* number of entries in SLB */
        mtctr   r0
        li      r6,0
        addi    r7,r9,VCPU_SLB
-       li      r5,0
 1:     slbmfee r8,r6
        andis.  r0,r8,SLB_ESID_V@h
        beq     2f
@@ -1309,7 +1323,7 @@ mc_cont:
        addi    r5,r5,1
 2:     addi    r6,r6,1
        bdnz    1b
-       stw     r5,VCPU_SLB_MAX(r9)
+3:     stw     r5,VCPU_SLB_MAX(r9)
 
        /*
         * Save the guest PURR/SPURR
@@ -1558,8 +1572,10 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
 BEGIN_FTR_SECTION
        ld      r5, STACK_SLOT_TID(r1)
        ld      r6, STACK_SLOT_PSSCR(r1)
+       ld      r7, STACK_SLOT_PID(r1)
        mtspr   SPRN_TIDR, r5
        mtspr   SPRN_PSSCR, r6
+       mtspr   SPRN_PID, r7
 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 
        /*
@@ -1671,6 +1687,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
        isync
 
        /* load host SLB entries */
+BEGIN_MMU_FTR_SECTION
+       b       0f
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
        ld      r8,PACA_SLBSHADOWPTR(r13)
 
        .rept   SLB_NUM_BOLTED
@@ -1683,7 +1702,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
        slbmte  r6,r5
 1:     addi    r8,r8,16
        .endr
-
+0:
 #ifdef CONFIG_KVM_BOOK3S_HV_EXIT_TIMING
        /* Finish timing, if we have a vcpu */
        ld      r4, HSTATE_KVM_VCPU(r13)
@@ -1710,8 +1729,12 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
  * reflect the HDSI to the guest as a DSI.
  */
 kvmppc_hdsi:
+       ld      r3, VCPU_KVM(r9)
+       lbz     r0, KVM_RADIX(r3)
+       cmpwi   r0, 0
        mfspr   r4, SPRN_HDAR
        mfspr   r6, SPRN_HDSISR
+       bne     .Lradix_hdsi            /* on radix, just save DAR/DSISR/ASDR */
        /* HPTE not found fault or protection fault? */
        andis.  r0, r6, (DSISR_NOHPTE | DSISR_PROTFAULT)@h
        beq     1f                      /* if not, send it to the guest */
@@ -1788,11 +1811,23 @@ fast_interrupt_c_return:
        stb     r0, HSTATE_IN_GUEST(r13)
        b       guest_exit_cont
 
+.Lradix_hdsi:
+       std     r4, VCPU_FAULT_DAR(r9)
+       stw     r6, VCPU_FAULT_DSISR(r9)
+.Lradix_hisi:
+       mfspr   r5, SPRN_ASDR
+       std     r5, VCPU_FAULT_GPA(r9)
+       b       guest_exit_cont
+
 /*
  * Similarly for an HISI, reflect it to the guest as an ISI unless
  * it is an HPTE not found fault for a page that we have paged out.
  */
 kvmppc_hisi:
+       ld      r3, VCPU_KVM(r9)
+       lbz     r0, KVM_RADIX(r3)
+       cmpwi   r0, 0
+       bne     .Lradix_hisi            /* for radix, just save ASDR */
        andis.  r0, r11, SRR1_ISI_NOPT@h
        beq     1f
 BEGIN_FTR_SECTION